This invention relates generally to devices which protect damage to objects during transport and lifting and, more specifically, to devices which protect damage to coatings applied to the surfaces of objects and which protect polished aluminum, stainless steel, or other materials that would have to be re-polished if damaged to renew an acceptable finish.
Many objects have delicate or easily damaged surfaces, including but not limited to protective or decorative surfaces, and handling and transporting those objects in many cases leads to some degree of damage to the surface. A worst case example is the surfaces of objects such as fuel cylinders, tanks or vessels (“vessels”) painted or coated with high temperature coatings. The high temperature coatings are “soft” until fully cured with heat-induced cross-linking and many having a pencil hardness of 4B or softer. Additionally, the high temperature coatings are thermoplastic, meaning they can soften when exposed to heat, including direct sunlight. To make matters worse, in many cases the vessel must be transported or lifted when the coating is in a dry but uncured state. In the case of high temperature coatings, when the vessel arrives at the customer, the entire vessel (or significant areas of it) must be stripped and recoated to meet the specification and provide adequate corrosion control and an aesthetically pleasing finish.
Cargo straps, the most common means used to secure loads on flat bed trailers, are typically made of woven nylon (textured) material that stretches until tightened and secured. A 4-inch wide cargo strap may only have a 1-inch wide contact area, located at the peak of the strap's texture and putting the entire force when secured in a much smaller area. During tightening and after the strap is secured, the strap tries to (and will under tension) “self-center” between the two tie-down points, thereby relative to the coated surface and causing damage and the texture “telegraphs” itself to the surface (see FIG. 1). This kind of damage can occur to coated surfaces even after curing.
To date, no effective solution exists which protects the coating. Manufacturers and customers simply accept damage to coatings as “the way it is,” that delicate or painted surfaces will encounter unsightly damage when lifted or secured for transportation and must undergo costly repairs to have an aesthetically pleasing finish.
Not transporting or lifting the vessel until the coating is fully cured is not practical because vessel manufacturers are under pressure to deliver on time and often do not have the luxury of time. And many coatings, especially liquid coatings, require weeks or even a month to fully cure. even if fully cured the coating is prone to damage as the strap's texture bites into the coating or the strap self-centers. Placing padding such as foam, carpet, plastic and rubber bumpers between the cargo strap and the coating has been tried but it also does not work. The strap's contact area is still concentrated over a small area of the padding, the coating itself is not smooth, additional tightening is now required to accommodate the padding yet secure the object, and the strap still self-centers, as well as stretches, but now moves the padding with it.
Similarly, other objects with delicate or easily damaged surfaces such as those having painted surfaces, polished aluminum or stainless steel finishes, or hard protective or decorative surfaces can be damaged in much the same way as objects with high temperature coatings. The heavier the object the more difficult it is to protect it from damage during transport. Therefore, a need exists for a practical, effective solution.